Shoest acting synthetic opioid is
**Core Concept**
The question is testing the knowledge of synthetic opioids, specifically their duration of action. Synthetic opioids are man-made substances designed to mimic the effects of natural opioids, such as morphine. They work by binding to opioid receptors in the brain, which alters the perception of pain.
**Why the Correct Answer is Right**
Fentanyl is a synthetic opioid that is known for its rapid onset and short duration of action. It is approximately 50-100 times more potent than morphine and is often used in anesthesia and pain management. Fentanyl's short duration of action is due to its high lipid solubility, which allows it to quickly cross the blood-brain barrier and bind to opioid receptors. However, its effects are short-lived, requiring frequent administration to maintain therapeutic levels.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because the duration of action of this opioid is not the shortest among the synthetic opioids.
**Option B:** This option is incorrect because the duration of action of this opioid is not as short as fentanyl, and it is not the shortest among the synthetic opioids.
**Option C:** This option is incorrect because the duration of action of this opioid is not the shortest among the synthetic opioids.
**Clinical Pearl / High-Yield Fact**
Fentanyl's short duration of action requires careful dosing and frequent administration to maintain therapeutic levels, making it a high-risk medication for overdose and respiratory depression.
**Correct Answer: D. Fentanyl**